Recently, a majority of image reading apparatuses for reading an image of a document are equipped with an auto-document feeder (ADF) that automatically receives and feeds the document. When a document is read by using the ADF, light is irradiated to the transferred document through a reading window, and reflected light from the document is obtained through the reading window, and image data of the document is generated based on the obtained reflected light.
However, in such a case, the transferred document may come into contact with the reading window to contaminate the reading window. Specifically, toner, ink, particulates or the like of the transferred document are attached to the reading window to form, for example, a stripe pattern on the generated image data.
To cope with these problems, Japanese Patent Application Laid-Open No. 2010-56721 discloses an image forming apparatus in which a dust detection reference member disposed at an upper side of a contact glass (a reading window) is read through a traveling body when a reading operation performed on a document is terminated, dust between the traveling body and the dust detection reference member is detected based on the read image, and when dust is present, a corresponding purport is reported to a user.